This invention relates to a lock assembly for a wearable structure and, more particularly, to a replaceable assembly consisting of a base part and a wear part for protecting a face of a structure engageable with abrasive material. The face so protected is usually flat, i.e., planar or slightly arcuate, as contrasted to the lip or wing protected by the wear part in the above-identified application.
The invention finds utility in connection, for example, with excavating equipment, ore chutes used in mining and other structures subject to abrasive wear. The continuing problem is to provide a part that engages the abrasive material which is securely locked in place during operation yet which is easily replaced when worn. The locks of the prior art often employed resilient keepers or plugs engageable with a pin and imposition of shock loads in combination with abrasion resulted in lock deterioration. Other locking procedures made replacement more difficult as did the welded stops of co-owned patent RE 33,454.
According to the invention, disadvantages of the prior art locks have been overcome through the provision of a relatively elongated wear part having first and second generally planar longitudinally extending surfaces which extend from one end of the wear part to the other. In this aspect, the instant invention differs from that of the above mentioned application where the wear part had a generally J or C shape to wrap around the lip or wing of an excavator, for example.
One of the wear part surfaces herein faces the abrasive material and the other has coupling means such as a tongue or groove for engaging a complementary shape on the base part. The base part is connected to the generally continuous face of the structure to be protected, continuous such as planar but also including slightly arcuate as is found at the rear of a dragline bucket.
In one advantageous embodiment, the inventive lock finds effective application to wearable parts such as wear runners for buckets and chute liners using coupling means such as the dovetails seen in co-owned U.S. Pat. Nos. 33,454 and 5,005,304. The coupling means not only can include sloping surfaces (as in dovetails) but can also employ T-shapes as shown and described in the above-mentioned application. In the latter instance, there are transversely extending, spaced apart walls which are parallel to the generally planar face of the structure to be protected. Thus, in either case, there are transversely spaced longitudinally extending coupling surfaces which prevent movement of the wear part away from the base part.
Each of the tongue and groove is equipped with at least one transverse wall, with these walls being spaced apart and an essentially non-compressible lock mounted between them. The lock is equipped with a laterally extending latch which cooperates with keeper means on either part for maintaining the lock in place. The wear part is equipped with an opening for the insertion of the lock.